Novel gas sensing mechanisms of Pd and Rh-doped h-BN monolayers for detecting dissolved gases (H、CH、and CH) in transformer oil.

Detecting dissolved gases in transformer oil is crucial for assessing the operational status of transformers. The gas composition in transformer oil can reflect the health status of the equipment and help identify potential failure risks in a timely manner. Based on density functional theory (DFT), Pd and Rh atoms were doped into the h-BN monolayer, and the most stable adsorption structures for each were first explored. Then, the sensing performance of the Pd-doped and Rh-doped h-BN monolayers for H, CH, and CH gases was analyzed. The results indicate that Pd-BN and Rh-BN exhibit enhanced sensitivity to H and CH gases compared to pristine h-BN. However, they show poor adsorption characteristics for CH. Both Pd-BN and Rh-BN demonstrate strong chemisorption for H and CH. In contrast, CH adsorption is predominantly physisorbed. The desorption time of H from Pd-BN at 398 K is 164 s, reflecting its excellent desorption performance. Additionally, Pd-BN and Rh-BN monolayers exhibit exceptional CH capture capabilities, with adsorption energies of -1.697 eV and -2.188 eV, respectively, indicating their potential as CH gas adsorbents. These findings provide theoretical insights for selecting materials for dissolved gas detection in oil and lay the groundwork for the development of Pd-BN and Rh-BN-based gas sensors.